Oscillograph circuit



April 9, 1940. ANDR 2,196,845

OSCILLOGRAPH CIRCUIT Filed March 19, 1937 25 I I I I I I I Cathode 1Tube 'wvyvw|l| 25 25 10 III- T (hf/lode 0 Ray 1: 2 Tube :2 8 Q l I -Ilh-13 25 INVENTOR ROBERT ANDRIEU ATTORNEY Patented Apr. 9, 1940 UNITEDSTATES f .Z 96 8 5f 2,196,845 OSCILLOGRAPH clncurr Robert Andrieu,Berlin, Germany, assignor to Telefunken Gesellschaft fiir 'DrahtloseTelegraphic in. b. H., Berlin, Germany, a corporation of GermanyApplication March 19, 1937,Serial No. 131,875

In Germany March 27', 1936 a 3 Claims. (o 250-46) A sawtooth shapedpotential is required for the recording of periodically recurringelectrical actions by a Braun oscillograph if Lissajous figures whichare generally not evaluable without retracing are to be avoided, and thefrequency of the potential must be equal to, or be a multiple of,

the frequency of the action to beinvestigated or analyzed. quency of thepotential should be easily adjustable. Moreover, with the use ofstandard Braun tubes in which the pencil strikes about the middle of thefluorescent screen in the non-deflected or quiescent state of the pencilit is very necessary that the sawtooth voltage wave should be symmetricin shape and trend, in other words, it must be free from D. 0.components.

My invention in general provides a regenerating oscillating tubearrangement having an oscillatory circuit joined to the anodeof saidtube, 20 sinusoidal waves generated by the oscillator being fed to avacuum tube acting as a discharge path for a condenser in which chargesare linearly stored and discharged. The condenser resistance combinationby means of which the condenser is charged comprises a time constantcircuit which is mechanically interlocked with the aforementionedoscillatory circuit so that these two circuits are maintained in adefinite relationship each with the other. e

My invention will bestbe understood by reference to the figures in whichFig. 1 shows one embodiment of my invention, and 35 t Fig. 2 showsanother embodiment of my invenion.

Referring to Fig. 1 of the accompanying drawing, a vacuum tube III hasan oscillation circuit I I connected in the anode thereof, said circuit40 including the condenser l2 and the'choke coil I3. A regeneration(feedback) coil I5 is 'con nected to a condenser M which is joined withthe grid of the tube H). A grid leak acts as a leak path for condenserI4. The plate of tube I0 is 45 connected by way of a coupling condenserH with the control grid of a tube l8. The latter also has a grid leakl9. In parallel connection with the tube i8 is a condenser 20. The plateand the filament of tube l8 are respectively con- 50 nectedby way of tworesistances 2|, 22 of like size with the positive and'the, negativepole, respectively, of a source of D. C. voltage, this source beinggrounded at a suitable point. In parallel relation to the said tube 18by way of coupling 86 condenser 23 is the deflector plate system of theIt is convenient also that the fre earthed by way of resistances 25.

The arrangement shown in Fig. 1 operates'in oscillograph tube 24, thedeflector plates being the manner that on the control grid of tube [8,

by way of coupling condenser I1, is impressed a; t

sinusoidal potential to ground. When'the said potential presents a crestvalue with reference to the filament of tube l8, flow of grid current Iwill be initiated which sets up the requisite negative grid biasingpotential on one side of con- 10 denser l1, the latter being caused toleakaway again gradually by way of the resistance .I9. The condenser 20is constantly charged by way of resistances 2|, 22, the condenserpotential showing 'a rise proportional to time, when start- 'ing fromzero potential across condenser or from an initial voltage which issmall compared with the source of charge potential. Upon each initiationof discharge inthe tube |8,the condenser 20 is discharged through thesaid tube, down to. 24! the value at which the plate current as a resultof decline of plate potential becomes interrupted or down to the valuewhen the control grid poten-' tial of tube I8 liesagain below the lowerbend of the plate current grid voltage characteristic. 25 If tubel8 is agrid-controlled gas or vapor type discharge vessel with an arc-likedischarge, it is generally possible to produce lower minimum values ofpotential at the condenser 20, thanin a case where tube I8 is of thehigh-vacuum type. 'Ihe sawtooth shaped alternating voltage arisingacross the condenser 2|] consists of a D. C. com- 'ponent which arisesacross the blockingcondensers23and a symmetric sawtooth component whichin major art is operative at the deflector I plates, of theBraun tube.The resistances 25 moreover have this action that a D. C. voltagepossibly set up across the-deflector plates. as a result of creepage orsneak currents is allowed to leak away. e The frequency of the sawtoothvoltage may be regulated in a particularly simple manner by I that thesetting means for the condensers I2 and 20 aremechanically coupled orinterlocked, an end which is attainable inpractice by that the rotorparts of both condensers are seatedu pon, one and the same shaft. Inanother exemplified embodiment. of the invention as shown in Fig. 2 acoupling by theaid of a transformer ZS-is used in lieu of thecapaciexplained by reference to Fig. 1. j Also the chance of couplingthe two condensers 20 and I2 is the same as described by reference toFig. 1.

What I claim is: I

1. An apparatus for producing energizing potentials comprising anoscillator, an electric storage element, means for storing a charge insaid storage element, a discharge path for said storage element, meansfor coupling the oscillator to said discharge path, and means forsimultaneously varying the storage rate of said storage element and thenatural frequency of said oscillator v 2. An apparatus for producingenergizing potentials comprising an oscillator, an electric storageelement, means for storing a charge in said storage element, a dischargepath for said storage element, a time constant circuit connected to saiddischarge path, means for coupling said discharge path and said timeconstant circuit to said oscillator, and means for simultaneouslyvarying the storage rate of said storage element and the naturalfrequency of said oscillator.

I 3. An apparatus for producing energizing potentials comprising anoscillator having an oscillatory circuit therein, an electric storageelement,

ROBERT ANDRIEU.

